Mark 7:21-23
V. 21. For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders, V. 22. thefts, covetousness, wickedness, deceit, lasciviousness, an evil eye, blasphemy, pride, foolishness: V. 23. all these evil things come from within, and defile the man.
The lesson which Christ wanted to teach lay deeper; the physical side of the process touched upon by Him was only aside issue. That upon which all depends is the right attitude, the proper understanding of the things that go out from the body. From inside, from the heart, which is full of evil and inclined toward all evil by nature, come thoughts, desires, words, actions that defile the man.
God looks into the heart. It is not only the actual sin which is culpable in His sight, but the very thoughts are bad, wrong, sinful before Him. And they all live in the heart:
adulteries, open disruptions of the marriage-rights;
thefts, the unlawful desire and gain of the neighbor's goods;
murders, any thoughts or acts that make the neighbor's life unpleasant or destroy it;
fornications, actual severing of the marriage-tie;
covetousnesses, striving after goods that belong to the neighbor by God's gift or permission;
wickednesses, all forms of evil dispositions;
fraud, by which people try to get the best of their neighbor;
debauchery, in which men serve their own bodies in a manner unbecoming Christians and human beings;
an evil eye, jealousy, which begrudges the other person everything good; blasphemy, by which God is mocked and all that is holy is defiled;
presumption, the lifting of one's self above the neighbor;
lack of knowledge, moral foolishness.
The seed, the germ of all these sins, lies in the heart of every man by nature, only awaiting the occasion when it will come forth and work havoc. These are the things that defile a person, but not any form of the so-called Levitical or ceremonial uncleanness. A Christian has need to watch over his heart unceasingly, lest any of these evil seeds sprout and grow beyond all control.